How Much Flooring Do I Need?
Enter your room size, layout, and box coverage to get exact square footage and boxes to buy — works for LVP, hardwood, laminate, tile, and carpet.
⚡ Quick Answer
A 10×12 room (120 sq ft) needs 132 sq ft with 10% waste for a straight lay — or 138 sq ft for a diagonal layout. Enter your box coverage below to get the exact number of boxes to buy.
Room Dimensions
Box coverage is printed on the package — typically 15–25 sq ft per box for planks, 10–15 sq ft for tile.
Square Feet Needed
—
sq ft (including waste)
—
sq ft (including waste)
Room Area—
Boxes to Buy—
Waste Added—
Box Coverage—
How Much Waste to Add?
10% — Straight lay, simple room shape
15% — Diagonal cuts, L-shaped rooms
20% — Herringbone, complex patterns
10% — Carpet (any layout)
10% — Straight lay, simple room shape
15% — Diagonal cuts, L-shaped rooms
20% — Herringbone, complex patterns
10% — Carpet (any layout)
When in doubt, add 15%. Running short mid-job is costly if dye lots have changed.
How to Measure Your Room
Measure at the widest points — include closets and alcoves separately.
Measure at the widest points — include closets and alcoves separately.
For irregular rooms, break them into rectangles, calculate each, then add together.
Always measure twice. A 1-foot error on a 20×20 room adds 20 sq ft and 1+ boxes.
Buy Extra — Same Dye Lot
Flooring color varies between production runs. Buy at least one extra box from the same dye lot for future repairs.
Flooring color varies between production runs. Buy at least one extra box from the same dye lot for future repairs.
Store extras flat in a climate-controlled area — not a garage or basement with humidity swings.
Flooring Reference — Square Feet by Room Size
Square feet needed including waste · Round up to nearest full box for your product
| Room Size | Room Area | 10% Waste | 15% Waste | 20% Waste |
|---|---|---|---|---|
| 8 × 10 | 80 sq ft | 88 sq ft | 92 sq ft | 96 sq ft |
| 10 × 10 | 100 sq ft | 110 sq ft | 115 sq ft | 120 sq ft |
| 10 × 12 | 120 sq ft | 132 sq ft | 138 sq ft | 144 sq ft |
| 12 × 12 | 144 sq ft | 159 sq ft | 166 sq ft | 173 sq ft |
| 12 × 14 | 168 sq ft | 185 sq ft | 194 sq ft | 202 sq ft |
| 14 × 16 | 224 sq ft | 247 sq ft | 258 sq ft | 269 sq ft |
| 15 × 20 | 300 sq ft | 330 sq ft | 345 sq ft | 360 sq ft |
| 20 × 20 | 400 sq ft | 440 sq ft | 460 sq ft | 480 sq ft |
Values rounded up. Divide by your box coverage to get boxes needed — e.g. 132 sq ft ÷ 20 sq ft/box = 7 boxes.
Frequently Asked Questions
How much flooring do I need for a 10×12 room?
A 10×12 room has 120 square feet. With a standard 10% waste allowance for a straight lay, you need 132 square feet of flooring. For a diagonal layout add 15% for 138 sq ft.
How much extra flooring should I buy for waste?
Add 10% for straight layouts. Add 15% for diagonal cuts or L-shaped rooms. Add 20% for herringbone or complex patterns. Always round up to the nearest full box.
How do I calculate how many boxes of flooring I need?
Multiply room length × width. Multiply by your waste factor (1.10 for 10%). Divide by the square footage per box on the package, then round up to the nearest whole box.
Should I buy extra flooring for future repairs?
Yes. Buy at least one extra box from the same dye lot. Flooring colors vary between production runs. Store extras flat in a climate-controlled area.
What is the formula for calculating flooring?
Square feet needed = (room length × room width) × (1 + waste factor). For a 12×14 room with 10% waste: 12 × 14 × 1.10 = 184.8, rounded up to 185 square feet. Divide by box coverage to get boxes.
Does flooring type affect how much I need to buy?
The floor type does not change the square footage formula but affects the recommended waste factor. Planks need 10–15% waste. Tile needs 10% for straight lay and 15%+ for diagonal. Carpet typically uses 10%.
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